Fly into Ljubliana or Venice (and then train out when we depart to Munich)

Keep in mind that if renting in Venice, you need to add the cost of Italian tolls into the equation (2x €10), as well as a toll sticker for Slovenia (€15 for 7 days, €30 for a month). If going through Ljubljana, the former is avoided and the latter already provided with the rental car. Rental car rates are probably more expensive in Venice than in Ljubljana, too.

On a side note - do I understand correctly that you're going to Slovenia to visit mostly just Lipica?

Hi Dejan,
Excellent points, thank you. And yes, the Slovenian leg of a larger European trip was initially inspired by Lipica (my daughters are equestrians so they will ride there as well as observe the training/exhibition opportunities and I grew up with a fascination for Lippizaners, so visiting the stud is of particular interest to us - honestly we drive my husband crazy as any trip involves horses...we'll ride in the UK first, and then stay at a Hafflinger Stud in Austria too) but of course now that I'm planning the trip there is so much more to see/do - if you are familiar with the area I'd love any input!

Thanks,
Marisa

If you're not planning to spend time in Venice, then I'd definitely fly to Ljubljana and keep it all within Slovenia. I also recommend the Radlovica beekeeping museum, if you're not yet aware of it.

How to Look Up Train Schedules and Routes Online gives you the DB train schedule link, which sells tickets for both trains and direct buses from Ljubljana to Munich.

If it's more convenient for you to fly right to Trieste, I see from the airport's Wikipedia page that there are Ryanair flights from London Stansted to Trieste.

There is so much to see and do in the area - Ljubljana itself, Piran on the coast, one of the caves such as Skocjan or Postojna and Predjama Castle, the Julian Alps with lakes Bled and Bohinj and the Soca Valley, the Goriska Brda and Vipava Valley wine regions, etc. All these places are within two hours of Lipica.

Seeing as you're equestrians, the Soca Valley has a small side valley called Lepena, where there's a rustic Alpine retreat called Pristava Lepena. Look into it, there's a focus on horseback riding and the whole place is very pretty and scenic, you might enjoy it, as well as being a great place to stay when exploring the rest of the valley.

Thank you so much Dejan and everyone for some fantastic insights!
Marisa

My wife and I rented a car from Venice and drove up to Slovenia last November. We stopped in Lipica after Kobarid and then on to Predjama castle and Piran for the first day of our trip. My wife loved that when we entered the Lipica farms, we pulled our car over, and dozens of friendly horses came by to visit with us. The farm is absolutely beautiful. We didn't stop at the stables but did see a lot of horses. Years before I did visit the stables with my cousin (from Slovenia) but did not see the show. Central Ljublanja is nice (especially with relatives as guides) but I always thought Bled, Bohinj, and Triglav park were breathtaking.